Adjustably coupled radio frequency transformer

ABSTRACT

An adjustably coupled transformer comprising a one-piece coil form, preferably a cylindrical form, made of a plastic material, having two sections separated by an integral deflectable part to permit the axial adjustment of one of the form sections relative to the other, a transformer winding being mounted on each of the coil form sections adjacent the deflectable part, with means for axially adjusting one of the coil form sections relative to the other. The transformer structure is mounted in a transformer housing.

O United States Patent [151 3,662,306 Heinis 1 May 9, 1972 s41ADJUSTABLY COUPLED RADIO 3,428,929 2/1969 Brown et al ..336/l29FREQUENCY TRANSFORMER 3,437,968 4/1969 Hildebrandt ..336/1 19 [72]Inventor: Robert P. Heinis, Totowa, NJ. Primary ExaminerThomas J. Kozma[73] Assignee: General Instrument Corporation, Newark, Atwmey James &Franklm Ni 57 ABSTRACT [22] Filed: 1971 An adjustably coupledtransformer comprising a one-piece [21] APPL 127,566 coil form,preferably a cylindrical form, made of a plastic material, having twosections separated by an integral deflectable part to permit the axialadjustment of one of the [52] U.S.Cl ..336/ll9,336/129,336/13] formsections relative to the other, a transformer winding [5 [1 Int. Cl...H0ll 21/04, H0lf2 l/06 being mounted on each of the coil form sectionsadjacent the [58] Field of Search ..336/l l5, 1 17, l 18, 1 I9, 129,deflectable part, with means for axially adjusting one of the 336/130,l3 1, I36 coil form sections relative to the other. The transformerstructure is mounted in a transformer housing. [5 6] References Cited 6Claims, 8 Drawing Figures PATENTEDMAY 9 I912 3. 662,306

' sum 1 or 2 INVENTOR 605627 f/E/ll/LS BY $0M ATTORNEYS ADJUSTABLYCOUPLED RADIO FREQUENCY TRANSFORMER This invention relates to anadjustably coupled transformer and more particularly to an adjustablycoupled double tuned radio frequency transformer.

It is known in the prior art to devise adjustably coupled radiofrequency transformers embodying a variety of structural forms. Thus, itis known to provide coil forms which telescope one relatively to theother in order to adjust the coupling between the-transformer coils, orcoil forms which embody threaded means for accomplishing the positionalchange in the transformer coils, or forms which include screwsaccessible from the outside of the coil assembly for effecting the"adjustable couplingof the transformer coils. It is also known to providea transformer structure in which the adjustment of the coupling betweentransformer coils is achieved by thedeforrnation ofparts between thesaid coils.

The prime object of my present invention relates to the provision of anadjustably coupled transformer and more particularly to an adjustablycoupled double tuned radio frequency transfonner embodying the followingstructural features, devised as improvements in construction operationand use of the adjustably coupled transformers of the stated prior art:

1. An adjustably coupled transformer comprising a onepiece coil form,preferably a cylindrical form, made of a plastic material, having twosections separated by an integral deflectable part to permit the axialadjustment of one of the form sections relative to the other, atransformer winding being mounted on each of the coil form sectionsadjacent the deflectable part, with means for axially adjusting one ofthe coil form sections relative to the other;

2. An adjustably coupled transformer having this described structure inwhich the transfonner is double tuned by the provision of a paramagneticcore mounted directly on the inner wall of each of the coil sections ofthe cylindrical coil form, the cores being mounted for axial adjustmentrelative to the transformer windings on the coil sections; and

3. An adjustably coupled transformer of the structure described in whichthe coil form and all of its parts are enclosed and mounted in atransformer housing with means for mounting the same in the housing inways to pennit the ready relative adjustment of the coil form sectionsfrom the outside of the housing as well as the ready adjustment of thetransformer cores from the outside of the housing.

To the accomplishment of the foregoing objects and such other objects asmay hereinafter appear, the invention relates to the adjustably coupledtransformer as is more particularly defined in the appended claims takentogether with the following description and the appended drawings inwhich:

FIG. I is a front elevational-view of the adjustably coupled transformerof the invention with a part cut away to expose parts of the coil-formand coil winding construction thereof;

FIG. 2 is a top plane view of FIG. 1;

FIG. 3 is a side elevational view of the transformer structure;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is an elevational view of the transformertaken in cross-sectionin the plane of the line 5--5 of FIG. 1' showing the sections of thecoil form andthe transformer coils or windings thereon-in one positionof adjustment;

FIG. 6 is a view of the transformer taken in cross-sectionin the planeof the line 6--6 of FIG. 1 (a view similar to that of FIGS) showing thesections of the coil form and the coils or windings thereon in anotherposition of adjustment;

FIG. 7 is a view of the transformer taken in cross-section in the planeof the line 7-7 of FIG. 1, and

FIG. 8 is a view thereof taken in cross-section in the plane of the line8-8 of FIG. 1.

Referring now more in detail to the drawings and having reference firstto FIGS. 5 and ,6 thereof, the adjustably coupled transformer of theinvention comprises essentially a onepiece coil form generallydesignated as 10 having two sections 12 and 14 separated by an integraldeflectable part 16, the

latter to permit axial adjustment of one of the form sections relativeto the other, a transformer winding 18 being mounted on one of the saidsections such as the coil form section 12 and a transformer winding 20being mounted on the other section, namely, the coil form section 14,both windings being mounted adjacent the deflectable coil form part l6.The coil form is preferably cylindrical in form and is made of aflexible plastic material such as polypropylene; and the deflectablepart 16 is produced by axially slitting a cylindrical part of the coilform and deforming the same-into the shape or formation best depicted inFIG. 5 of the drawings. With this construction the coil sections 12 and14 may readily be adjusted axially relative to each otherto change thelength of the overall coil form and toadjust the position of thetransformer winding 18 with reference'to the transformer winding '20,relative adjustment of these parts effecting the relative movementthereof between the position shown in' FlG. 5 and the position shown inFIG. 6 of the drawings.

The transformer is preferably a double tunedftransformer; and to thisend each of the coil form sections (12, '14) is provided with aparamagnetic core mounted and axially adjustable within its coil formsection, for axial adjustment relative to the transformer winding onsuch section. Thus, the coil section 12 is provided with theparamagnetic core 22 and the coil form section 14 is provided with theparamagnetic core 24, each of which is directly mounted, and axiallyadjustable, as clearly shown in FIGS. 5 and 6, on the inner wall of thecoil form 10, the cores 22 and 24 being externally threaded for thispurpose as shown andthe inner walls of the coil sections 12 and 14 beingformed with integral ribs 26 co-acting with the external threads of thecores 22 and 24.

The transformer structure described also has incorporated thereon themeans for axially adjusting the coil form sections relative to eachother. This partakes of a part 28 secured to the outer wall of the coilform section 12 at its top. This part 28 preferably is in the form of acollar externally threaded as at 30, the collar being formed with radialextensions 32 for a purpose to be described.

Theadjustably coupled transformer described is enclosed and mountedwithin a transformer housing 34 having the shape and form clearly shownin the drawings. The coil form 10 is mounted in the housing 34 by theprovision of a base member 36 fixedly attached as at 38, 38 to thebottom of the housing, the bottom end of the coil form section 14 beingsecured to this base member at 40 as best shown in FIGS. 5 and 6 of thedrawings. In the top of the housing there is provided a member 42rotatably mounted in the top end of the housing, the said memberpreferably comprising a nut internally threaded at 44 for threadedconnection with the external threads 30 of the collar 28. The nut 42 isextended laterally as at 46 to engage the walls of the housing34 tostablize rotation of the same, and the housing is formed with lock tabs48, 48 which engage the extensions'46'to effect the captivation of thenut and to prevent axial movement thereof during nut rotation. The nutis further provided with a part 50 projecting through the top of thehousing 34, the said part being preferably formed as a hex' nut forreceiving a socket wrench 55 (FIG. 6) for effecting the rotations of thenut 42.

The collar 28 isformed with radial extensions 32, 32 (previouslyreferred to) which extend to engage the comers of the housing 34 (seeparticularly FIGS. 7 and 8) to prevent rota tion of the collar. As willnow be seen, rotation of the nut 42 will effect the constrained axialmovement of the collar 28 to in turn effect the axial adjustment ofthe-top coil form and winding thereon relative to the bottom coil formand its windmg.

With the adjusting means described, rotation of the nut 42' will readilyresult in the relative adjustments desired; and the collar 28 is soconstructed and supported as to prevent accidental damage to the unitwhen torque is applied to the ad'- justing nut at its extreme in the upposition; in the extreme down position the unit is protected by allowingthe threaded collar to completely disengage the nut; and to insurerethreading in this condition, a lead-in section is provided in thethreaded collar.

For axially adjusting the cores 22 and 24, these cores are formed withhexagonal shaped bores 52, 52 access to which by a suitable similarlyshaped tool may be obtained through a central opening 54 in the nut 50and a central opening 56 at the bottom of the coil form section 14.

Suitable terminals 58, 58 are embodied in the base member 36 to whichthe leads 60, 60 of the windings are attached.

The structure, use and operation and the advantages obtained in thefunctioning and use of the adjustably coupled transformer of theinvention will, it is believed, be fully understood from the abovedetailed description thereof. It will be further apparent that changesmay be made in the structure thereof without departing from the spiritof the invention defined in the following claims,

I claim:

1. An adjustably coupled transformer comprising a onepiece coil formhaving two sections separated by an integral deflectable part to permitof axial adjustment of one of the form sections relative to the other, atransformer winding on each of the coil form sections adjacent thedeflectable part, and means for axially adjusting one of the coil formsections relative to the other.

2. The adjustably coupled transformer of claim 1, in which the coil formis a cylindrical form made of a plastic material, the windings are radiofrequency transformer windings, the transformer being doubly tuned by aparamagnetic core mounted directly on the inner wall of each of the coilform sections for axial adjustment relative to the transformer windingon such section.

3. The adjustably coupled transformer of claim 1, in which the coilform, the windings thereon and the adjusting means are enclosed in atransformer housing, the axial adjusting means being fixed to one of thecoil form sections, a base member fixedly attaching the other coil formsection to one end of the housing, and a member rotatably mounted in theother end of the housing having a threaded connection with the axiallyadjusting means, rotation of said latter member operating the adjustingmeans for effecting the axial adjustment of one coil form sectionrelative to the other coil form section.

4. The adjustably coupled transformer of claim 1, in which the coil formis a cylindrical form made of a plastic material, the windings are radiofrequency transformer windings, the transformer being doubly tuned by aparamagnetic core mounted directly on the inner wall of each of the coilform sections for axial adjustment relative to the transformer windingon such section, the axial adjusting means being fixed to one of thecoil form sections, a base member fixedly attaching the other coil formsection to one end of the housing, and a member rotatably mounted in theother end of the housing having a threaded connection with the axialadjusting means, rotation of said latter member operating means foreffecting the axial adjusting of one coil form section relative to theother coil form section.

5. The adjustably coupled transformer of claim 3, in which the axialadjusting means comprises a threaded collar fixed to said one of thecoil form sections, the said threaded collar being provided withextensions engaging the inner walls of the transformer housing toprevent rotation of the collar and to permit axial sliding movementthereof within the housing, and the member rotatably mounted in thehousing comprising a nut threadingly engaging the said collar, the saidnut having extensions engaging part of the transformer housing forpermitting rotation of the nut and preventing axial movement of the nut.

6. The adjustably coupled transformer of claim 5 in which an axiallyadjustable paramagnetic core is mounted in each of the coil formsections, one of the cores being accessible from the outside of thehousing through an opening in the said nut,

the other core being similarly accessible through an opening in the coilsection in which it is mounted.

1. An adjustably coupled transformer comprising a one-piece coil formhaving two sections separated by an integral deflectable part to permitof axial adjustment of one of the form sections relative to the other, atransformer winding on each of the coil form sections adjacent thedeflectable part, and means for axially adjusting one of the coil formsections relative to the other.
 2. The adjustably coupled transformer ofclaim 1, in which the coil form is a cylindrical form made of a plasticmaterial, the windings are radio frequency transformer windings, thetransformer being doubly tuned by a paramagnetic core mounted directlyon the inner wall of each of the coil form sections for axial adjustmentrelative to the transformer winding on such section.
 3. The adjustablycoupled transformer of claim 1, in which the coil form, the windingsthereon and the adjusting means are enclosed in a transformer housing,the axial adjusting means being fixed to one of the coil form sections,a base member fixedly attaching the other coil form section to one endof the housing, and a member rotatably mounted in the other end of thehousing having a threaded connection with the axially adjusting means,rotation of said latter member operating the adjusting means foreffecting the axial adjustment of one coil form section relative to theother coil form section.
 4. The adjustably coupled transformer of claim1, in which the coil form is a cylindrical form made of a plasticmaterial, the windings are radio frequency transformer windings, thetransformer being doubly tuned by a paramagnetic core mounted directlyon the inner wall of each of the coil form sections for axial adjustmentrelative to the transformer winding on such section, the axial adjustingmeans being fixed to one of the coil form sections, a base memberfixedly attaching the other coil form section to one end of the housing,and a member rotatably mounted in the other end of the housing having athreaded connection with the axial adjusting means, rotation of saidlatter member operating means for effecting the axial adjusting of onecoil form section relative to the other coil form section.
 5. Theadjustably coupled transformer of claim 3, in which the axial adjustingmeans comprises a threaded collar fixed to said one of the coil formsections, the said threaded collar being provided with extensionsengaging the inner walls of the transformer housing to prevent rotationof the collar and to permit axial sliding movement thereof within thehousing, and the member rotatably mounted in the housing comprising anut threadingly engaging the said collar, the said nut having extensionsengaging part of the transformer housing for permitting rotation of thenut and preventing axial movement of the nut.
 6. The adjustably coupledtransformer of claim 5 in which an axially adjustable paramagnetic coreis mounted in each of the coil form sections, one of the cores beingaccessible from the outside of the housing through an opening in thesaid nut, the other core being similarly accessible through an openingin the coil section in which it is mounted.